What's the point of carbon? The bike is unavoidably heavy from batteries, motor and all the various kinds of beef needed to take the extra power, extra clothing and extra lard of the rider.

If there was a normal sized rear wheel they would not need as much from the suspension, and could reduce the front chainwheel and drop the BB a little. Are they just using the wee wheel as a way to get the unsprung weight nearer to something standard suspension can handle?

My guess is the evolution of off-road electrics will be: increasing power -> ripped up tracks -> banned some places -> more pressure on remaining tracks -> banned there too -> fit road tyres, change the gearing, lock out the suspension, try to get proper mudguards to fit.